1. Field of the Invention
The present invention generally relates to an improved bushing assembly for use in combination with electrical conduit. More particularly, the present invention relates to a bifurcated or dual-sectioned grounding bushing assembly, which grounding bushing assembly effectively allows electricians to install the grounding bushing assembly either before or after completing wiring connections at a junction box.
2. Description of the Prior Art
Bushings are typically installed on the terminal end of electrical conduit at an electrical junction box to serve as an aperture lining through which electrical conductors pass. Bushings are often required so as to reduce the likelihood that the electrical conducting materials will improperly contact either the junction box or conduit terminus. In other words, without a properly installed bushing in place, the electrical conductors may become damaged, leading to unsafe conditions. Grounding bushings have the additional function of providing the circuitry with a path to a zero potential with respect to the Earth.
As noted in U.S. Pat. No. 4,233,469 ('469 patent), wiring connections are, on occasion, mistakenly finalized before the bushing or grounding bushing is installed. Improper electrical installations such as those here identified must be remedied for safety reasons and thus on the occasion when a traditional, unibody, annular bushing member is omitted from an installation site, electricians must (1) disconnect the wiring, (2) feed the electrical conductors through the unibody bushing member, (3) properly reinstall the bushing member, and (4) reconnect the wiring. The described methodological error significantly increases the labor involved at a given job site, thus increasing costs to contractors and consumers alike. Methodological errors such as those here identified are difficult to completely eradicate given the occasional human error. The ramifications from these types of errors may be easily minimized, if a hinged bushing is utilized (See generally, for example, the '469 patent). The prior art also teaches a variety of devices to effect enhanced electrical grounds. Some of the more pertinent prior art relating to these subjects is described hereinafter.
U.S. Pat. No. 1,690,220 ('220 patent), which issued to Fahnestock, discloses a Ground Connector. The '220 patent teaches in relevant portion, a spike cooperatively associated with the internal surface of a ground connector. The spike is designed for piercing through surface materials located on conductive piping so as to make proper electrical contact between the ground connector and the piping. Further, the two ends of the ground connector comprise first and second screw-receiving portions for cooperatively receiving a tightening screw. When the tightening screw is removably inserted into the first and second screw-receiving portions for tightening the hinged grounding bushing in circumferential relationship to at least one current carrying wire, the spike makes proper electrical contact with the conductive piping.
U.S. Pat. No. 3,985,411 ('411 patent), which issued to Mooney et al., discloses a Hinged Ground Clamp. The '411 patent teaches an electrical conduit grounding assembly comprising a grounding cable and a pair of clamp members. Each clamp member is constructed from conductive material and comprises a hinge portion, a tightening portion, and an inner clamp surface. Each inner clamp surface comprises a teeth or ribs for making electrical contact with a conductive conduit. The hinge portions cooperatively form a hinge knuckle through which the grounding cable passes. A screw engages a tapped bore in each of the tightening portions to permit their tightening.
U.S. Pat. No. 4,189,198 ('198 patent), which issued to Reichman, discloses a Conduit Ground Wire Coupling. The '198 patent teaches a conduit coupling collar constructed of conductive materials having a threaded inside surface. Integrally formed with coupling collar is an axially inwardly inclined annular flange. A non-conductive bushing member is entrapped in the space delineated by the annular flange. A set screw or bolt is removably insertable through any of a plurality of tapped bores and fastens a clamp member to the coupling collar. The set screw makes electrically conductive contact with the threaded inside surface.
U.S. Pat. No. 4,223,469 ('469 patent), which issued to Steppe, discloses a Conduit Bushing. The '469 patent teaches a conduit bushing constructed from insulative materials comprising first and second bushing halves, hinge means, and latch means. Each bushing half comprises a latch portion and a hinge portion. The hinge means hingedly connect the first and second bushing halves at the hinge portions, and the latch means removably fasten the latch portions together.
U.S. Pat. No. 4,806,108 ('108 patent), which issued to Meinhardt, discloses a Grounding Bushing. The '108 patent teaches a grounding bushing constructed from conductive materials and thus permits grounding. The grounding bushing comprises an annular band, a threaded inner surface, and a plurality of raised bosses. Each boss comprises a set screw-receiving bore. A set screw is utilized to fasten a ground wire-receiving lug to the grounding bushing. When in a fastened state, the set screw makes electrically conductive contact between the lug, the bushing and a conductive conduit.
It will thus be noted that while the '469 patent does teach a hinged bushing, which bushing enables an installer to install the device either before or after electrical connections are finalized, the '469 patent does not teach a hinged grounding bushing. Grounding bushings, as opposed to insulative bushings, must communicate electrically with the terminal end of an electrical conduit adjacent an electrical junction box. That is, the grounding bushing must be constructed, at least in part, from electrically conductive materials, thus being able to serve as a bridge for migrating charges as they move to zero potential. The '469 patent does not address the structural peculiarities inherent in essential grounding bushing art. Further, while the '411 Patent does disclose a hinged ground clamp, it does not teach a hinged grounding bushing. From a review of the above-referenced patents and other prior art generally known to exist, it will be seen that the prior art does not teach a dual-sectioned grounding bushing for enabling installers to install the bushing either before or after electrical connections are finalized at a junction box.